Project Profile: Upgrading an Energy Substation for an Offshore Wind Farm

Jan. 6, 2017

Last March, the new Dillon’s Corner substation in Narragansett, RI, broke ground. Dillon’s Corner is a new substation from National Grid, one of the largest investor-owned energy companies in the world, covering Massachusetts, New York, Rhode Island, and the United Kingdom. The substation is one of many that will be updated and added to a network of existing substations working together in support of a new clean energy initiative featuring the first offshore wind turbine power source in the United States. National Grid partnered with Deepwater Wind to construct these wind turbines just off of Block Island; they will be used to power Block Island as well as a portion of Narragansett’s shoreline. As part of this project, many area substations will be updated or removed and new ones built to support a cleaner energy initiative.

Substations are a hub location where electricity that is transmitted over a long distance is converted from high to low voltage, or vice versa, and sent out through the distribution network. In addition, substations house several circuit breakers and fuses to protect the distribution networks so circuits may be isolated for maintenance and repairs without disturbing an entire distribution block. Dillon’s Corner is located on the property of an existing maintenance facility for the Rhode Island Department of Transportation, which is currently used as a storage facility for state-owned equipment.

Because of the addition of the substation to the current Department of Transportation (DOT) site, the existing drainage system needed to be upgraded to ensure it could handle extra runoff. Additionally, in keeping with their clean energy mission, project design engineers wanted to keep any stormwater runoff from flowing into the surrounding areas without being treated. The facility’s previous solution was conventional catch basins, which tied into an underground drainage system. With the addition of the substation, a more advanced stormwater management plan was required: a simple catch basin system would no longer suffice. The extra volume of stormwater that would be shed by the addition of the new substation could be best managed by a design upgrade to the infiltration system.

To satisfy the need for a stormwater system capable of handling such a large volume of runoff, the design team originally specified a 48-inch pipe system. However, a pipe system can be costly and labor intensive—and can sometimes be less environmentally friendly, in part due to a larger footprint requirement. As a result of prior success with Cultec’s stormwater chambers, the engineering team requested that Cultec be specified on the project as an alternate option. The Cultec system would be easier to construct and store onsite, in addition to being more cost effective and less disruptive to the environment. After some consideration, and in an effort to reduce not only the overall costs of the program but also the workload for the project contractors, the Cultec chambers were included in the site’s design. The chambers were able to meet the required storage, infiltrative, and routing requirements and were accepted as an alternative to the originally specified pipe system.

“This wasn’t our first time using Cultec, and we definitely will use them again,” says Scott O’Connor, project manager for J.H. Lynch and Sons Inc. “The installation went smoothly, with no challenges or problems.”

To satisfy site specifications and the challenge of potential large volumes of runoff, the design team selected Cultec’s Recharger 902HD chamber, a model that would accommodate the available workable area while maximizing storage capacity. The 902HD model stands 48 inches high, with a width of 78 inches and an installed length of 3.67 feet. The 186 chambers provided the substation with a total of 21,345 cubic feet of water storage and were installed in a 44.75- by 1,116.67-foot area. The system was designed to flow into the existing DOT drainage system from the in the event of an emergency overflow.

Cultec representatives were highly involved with the installation. Each stormwater project receives special attention and is treated uniquely. O’Connor notes, “Their sales representatives were very hands-on and out in the field supervising the installation on the first day, making sure the crew was familiar with the product. It’s an ideal company to work with.”

“Many of our customers know they can count on the Cultec team from start to finish on their project. This project is a perfect example of that,” says Bob Goodrich, a company representative. “As soon as we were notified, our technical design group reviewed the plans and converted the 48-inch pipe system over to a Cultec 902HD chamber system. Our sales team then quoted the system and offered a major cost savings by using chambers, which were booked and delivered directly to the job site on time by our shipping department. We make it a point to be on the site the first day to oversee and answer any questions during the installation process.”

The stormwater management installation was completed in June without any issues. The project will allow stormwater runoff on the Dillon’s Corner substation site to properly infiltrate into the system, and will operate effectively as part of the substation upgrades involved with the offshore wind turbine initiative. The chambers were provided by the Lincoln, RI, branch of EJ Prescott, an approved Cultec distributor. Construction on the entire project wrapped up in late 2016.